Strain effect on the electronic band structure of monolayer FeSe, a First Principle Study.

The high T_c cuprates and iron-based superconductors have been the hotspot of people's research for a long time. More interestingly, a really high T_c has been reached in the monolayer FeSe with the STO substrate, which has the simplest structure in iron-based superconductors. Strain engineering is one of the most convenient method to modify the electronic structure and the T_c. Here, in the framework of First Principle calculations, we studied the band structure evolution of monolayer FeSe under strain effect. The in-plane compressive and tensile strain cause the shift of hole and electronic pocket while layer bend leads to the renormalization of the bands near Fermi level, which are both expected to influence T_c.